midipix looks awesome, but seems to be GPL (not LGPL). Does that mean anything using it must be GPL too? I think that would be unacceptable for such a low layer of the stack.
After discussing this issue on #midipix on freenode, they had mentioned they will explore dual-licensing or some variant of such once the software is more stable and can be reliably deployed. In any case, the project is far too early in its infancy to start worrying about what license they might have.